Apparatus and method for transmitting acknowledgement information in a TDD communication system

ABSTRACT

Methods and apparatuses are described for transmitting acknowledgement information in a communication system. A method includes receiving one or more data TBs in one or more downlink data channels over TTIs; obtaining acknowledgement information comprising four acknowledgement information bits {0, 0, 0, 0}, jointly representing a state of reception results for a plurality of data TBs, wherein a number of the plurality of data TBs is greater than a number of the acknowledgement information bits, a UE is configured for reception of the one or more downlink data channels from two cells, and a number of the TTIs is three or four; Reed-Mueller (RM) encoding the acknowledgement information bits; and transmitting the RM encoded acknowledgement information bits on an uplink data channel. The state of reception results is represented as {NACK, any, any, any} and {NACK/DTX, any, any, any} for a first cell and a second cell of the two cells, respectively, or is represented as {NACK, any, any} and {NACK/DTX, any, any} for the first cell and the second cell, respectively, by the acknowledgement information bits {0, 0, 0, 0}.

PRIORITY

The present application is Continuation of U.S. application Ser. No.15/270,719, which was filed in the United States Patent and TrademarkOffice (USPTO) on Sep. 20, 2016, issued as Ser. No. 10/177,879 on Jan.8, 2019, which is Continuation of U.S. application Ser. No. 13/451,152,which was filed in the USPTO on Apr. 19, 2012, issued as U.S. Pat. No.9,450,709 on Sep. 20, 2016, and claims priority under 35 U.S.C. § 119(e)to U.S. Provisional Application No. 61/476,975, which was filed in theUSPTO on Apr. 19, 2011, the entire disclosure of each of which isincorporated herein by reference.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention relates generally to wireless communicationsystems, and more particularly, to the transmission of acknowledgementinformation in an uplink of a communication system.

2. Description of the Art

A communication system includes a DownLink (DL) that conveystransmission signals from a Base Station (BS or NodeB) to UserEquipments (UEs) and an UpLink (UL) that conveys transmission signalsfrom UEs to the NodeB.

More specifically, a UL conveys transmissions of data signals carryinginformation content, transmissions of control signals providing controlinformation associated with transmissions of data signals in a DL, andtransmissions of Reference Signals (RSs), which are commonly referred toas pilot signals. A DL also conveys transmissions of data signals,control signals, and RSs. UL signals may be transmitted over clusters ofcontiguous REs using a Discrete Fourier Transform Spread OrthogonalFrequency Division Multiplexing (DFT-S-OFDM) method. DL signals may betransmitted using an OFDM method.

UL data signals are conveyed through a Physical Uplink Shared CHannel(PUSCH) and DL data signals are conveyed through a Physical DownlinkShared CHannel (PDSCH).

In the absence of a PUSCH transmission, a UE conveys UL ControlInformation (UCI) through a Physical Uplink Control CHannel (PUCCH).However, when a UE has a PUSCH transmission, it may convey UCI with datathrough the PUSCH.

DL control signals may be broadcast or sent in a UE-specific nature.Accordingly, UE-specific control channels can be used, among otherpurposes, to provide UEs with Scheduling Assignments (SAs) for PDSCHreception (DL SAs) or PUSCH transmission (UL SAs). The SAs aretransmitted from the NodeB to respective UEs using DL ControlInformation (DCI) formats through respective Physical DL ControlCHannels (PDCCHs).

The NodeB may configure a UE through higher layer signaling, such asRadio Resource Control (RRC) signaling, a PDSCH, and a PUSCHTransmission Mode (TM). The PDSCH TM or PUSCH TM is respectivelyassociated with a DL SA or a UL SA, and defines whether the respectivePDSCH or PUSCH conveys one data Transport Block (TB) or two data TBs.

PDSCH or PUSCH transmissions are either scheduled to a UE by a NodeBthrough higher layer signaling or through physical layer signaling(e.g., a PDCCH) using a respective DL SA or UL SA, or correspond tonon-adaptive retransmissions for a given Hybrid Automatic Repeat reQuest(HARQ) process. Scheduling by higher layer signaling is referred to asSemi-Persistent Scheduling (SPS), and scheduling by a PDCCH is referredto as dynamic. A PDCCH may also be used to release an SPS PDSCH. If a UEfails to detect a PDCCH, this event is referred to as DiscontinuousTransmission (DTX).

The UCI includes ACKnowledgment (ACK) information associated with a HARQprocess (HARQ-ACK). The HARQ-ACK information may include multiple bitsindicating the correct or incorrect detection of multiple data TBs.Typically, a correct detection of a data TB is indicated by a positiveacknowledgment (i.e., an ACK) while an incorrect detection is indicatedby a Negative ACK (NACK). If a UE misses (e.g., fails to detect) aPDCCH, it may explicitly or implicitly (absence of a signaltransmission) indicate DTX (tri-state HARQ-ACK information) or both aDTX and an incorrect reception of a TB can be represented by a NACK (ina combined NACK/DTX state).

In Time Division Duplex (TDD) systems, DL and UL transmissions occur indifferent Transmission Time Intervals (TTIs), which are referred to assubframes. For example, in a frame including 10 subframes, some thesubframes may be used for DL transmissions and some may be used for ULtransmissions.

If a PDSCH conveys one data TB, respective HARQ-ACK informationtypically consists of one bit that is encoded as a binary ‘1’, if the TBis correctly received (i.e., an ACK value), and as a binary ‘0’, if theTB is incorrectly received (i.e., a NACK value). If a PDSCH conveys twodata TBs, in accordance with a Single-User Multiple Input MultipleOutput (SU-MIMO) transmission method, respective HARQ-ACK informationtypically consists of two bits [o₀ ^(ACK) o₁ ^(ACK)] with o₀ ^(ACK) fora first TB and o₀ ^(ACK) for a second TB.

FIG. 1 illustrates a conventional TTI for a PUSCH or a PUCCH.

Referring to FIG. 1, a TTI consists of one subframe including two slotsfor PUSCH 110A or PUCCH 110B transmission. Each slot 120A and 120Bincludes N_(symb) ^(UL) symbols 130A used for signaling data or HARQ-ACKinformation in a PUSCH, or N_(symb) ^(UL) symbols 130B used for HARQ-ACKinformation in a PUCCH, and Reference Signals (RS) 140A or 140B, whichare used for channel estimation and coherent demodulation of receiveddata or HARQ-ACK information. The transmission BandWidth (BW) consistsof frequency resource units that are referred to as Physical ResourceBlocks (PRBs). Each PRB consists of N_(sc) ^(RB) sub-carriers, orResource Elements (REs). For PUSCH transmission, a UE is allocatedM_(PUSCH) PRBs for a total of M_(sc) ^(PUSCH)=M_(PUSCH)·N_(sc) ^(RB) REs150A. For PUCCH transmission, a UE is allocated 1 PRB 150B, which may bein two different BW locations in each of the two subframe slots.

FIG. 2 illustrates a conventional HARQ-ACK transmission structure in aPUCCH subframe slot.

Referring to FIG. 2, HARQ-ACK bits b 210 modulate 220 a ConstantAmplitude Zero Auto-Correlation (CAZAC) sequence 230, for example, usingBinary Phase Shift Keying (BPSK) with b=b₀ or Quaternary Phase ShiftKeying (QPSK) with b=(b₀, b₁). The modulated CAZAC sequence is thentransmitted after performing an Inverse Fast Frequency Transform (IFFT)240. The RS is transmitted through a non-modulated CAZAC sequence afterperforming an IFFT 250.

FIG. 3 is a block diagram illustrating of a conventional transmitter fora PUCCH.

Referring to FIG. 3, a CAZAC sequence 310 can be used without modulationfor an RS or with modulation for HARQ-ACK information. The transmitterin the FIG. 3 includes a selector 320, a sub-carrier mapper 330, an IFFTunit 340, a Cyclic Shifter 350, a Cyclic Prefix (CP) inserter 360, and afilter 370 for time windowing. For sub-carrier mapping in thesub-carrier mapper 330, the selector 320 selects a first PRB and asecond PRB for transmission of the CAZAC sequence in a first slot and asecond slot, respectively. Subsequently, the IFFT unit 340 performsIFFT, and the Cyclic Shifter 350 applies a Cyclic Shift (CS) to theoutput of the IFFT unit 340. A CP and filtering are applied by the CPinserter 360 and the filter 370. Thereafter, the signal 380 istransmitted. Additional transmitter circuitry such as aDigital-to-Analog Converter (DAC), analog filters, amplifiers,transmitter antennas, etc., are not shown for brevity.

FIG. 4 is a block diagram illustrating a conventional receiver diagramfor a PUCCH.

Referring to FIG. 4, the receiver includes a filter 420 for timewindowing, a CP remover 430, a CS restorer 440, a Fast Fourier Transform(FFT) unit 450, a sub-carrier de-mapper 460, a selector 465, and amultiplier 470. An antenna (not shown) receives an analog signal andafter further processing units (such as filters, amplifiers, frequencydown-converters, and Analog-to-Digital Converters (ADCs) that are notshown for brevity), a digital received signal 410 passes through thefilter 420 and the CP remover 430. Subsequently, a CS is restored by theCS restorer 440, the FFT 450 unit applies FFT, for sub-carrier demappingin the sub-carrier demapper 460, a selector 465 selects REs in a firstPRB and a second PRB in a first slot and in a second slot, respectively,and a multiplier correlates 470 the REs with a replica of a CAZACsequence 480. The output 490 may then be passed to a channel estimationunit, such as a time-frequency interpolator, when a subframe symbolconveys a RS, or to a detection unit, when a subframe symbol conveys aHARQ-ACK signal.

Different CSs of a same CAZAC sequence provide orthogonal CAZACsequences and can be allocated to different UEs to achieve orthogonalmultiplexing of HARQ-ACK signal transmissions in the same PRB. If T_(s)is a symbol duration, the number of such CSs is approximately └T_(s)/D┘,where D is a channel propagation delay spread and └ ┘ is a floorfunction that rounds a number to its immediately lower integer.

In addition to orthogonal multiplexing of HARQ-ACK signals and an RS ina same PRB using different CS of a CAZAC sequence, orthogonalmultiplexing may also be in the time domain using Orthogonal CoveringCodes (OCC). For example, in FIG. 2, a HARQ-ACK signal can be modulatedby a length-4 OCC, such as a Walsh-Hadamard (WH) OCC, while an RS can bemodulated by a length-3 OCC, such as a DFT OCC (not shown). When usingan OCC, the multiplexing capacity per PRB increases by a factor of 3(determined by the OCC with the smaller length). The sets of WH OCCs{W₀, W₁, W₂, W₃}, and DFT OCCs {D₀, D₁, D₂}, are respectively

$\begin{bmatrix}W_{0} \\W_{1} \\W_{2} \\W_{3}\end{bmatrix} = {{\begin{bmatrix}1 & 1 & 1 & 1 \\1 & {- 1} & 1 & {- 1} \\1 & 1 & {- 1} & {- 1} \\1 & {- 1} & {- 1} & 1\end{bmatrix}\mspace{14mu}{{and}\mspace{14mu}\begin{bmatrix}D_{0} \\D_{1} \\D_{2}\end{bmatrix}}} = {\begin{bmatrix}1 & 1 & 1 \\1 & e^{{- j}\; 2{\pi/3}} & e^{{- j}\; 4{\pi/3}} \\1 & e^{{- j}\; 4{\pi/3}} & e^{{- j}\; 2{\pi/3}}\end{bmatrix}.}}$

Table 1 presents a mapping for a PUCCH resource n_(PUCCH) used for aHARQ-ACK signal and an RS transmission to an OCC n_(oc) and a CS α,assuming 6 CS per symbol and a length-3 OCC (with 3 CS used for eachOCC). If all resources within a PUCCH PRB are used, resources in animmediately next PRB can be used.

TABLE 1 PUCCH Resource Mapping to OCC and CS. OCC n_(oc) for a HARQ-ACKand for an RS CS α W₀, D₀ W₁, D₁ W₃, D₂ 0 n_(PUCCH) = 0 n_(PUCCH) = 6 1n_(PUCCH) = 3 2 n_(PUCCH) = 1 n_(PUCCH) = 7 3 n_(PUCCH = 4) 4 n_(PUCCH)= 2 n_(PUCCH) = 8 5 n_(PUCCH = 5)

A PDCCH is transmitted in elementary units that are referred to asControl Channel Elements (CCEs). Each CCE may consist of 36 REs. UEs areinformed of a total number of CCEs, N_(CCE), through a transmission of aPhysical Control Format Indicator CHannel (PCFICH) by a serving NodeB.The PCFICH indicates a number of OFDM symbols used for PDCCHtransmissions in a respective DL subframe. A one-to-one mapping canexist between PUCCH resources (PRB, CS, OCC) for HARQ-ACK signaltransmission and PDCCH CCEs. For example, if a single PUCCH resource isused for HARQ-ACK signal transmission, it may be derived from the CCEwith the lowest index in a PDCCH conveying a respective DL SA.

In TDD systems, DL and UL transmissions occur in different subframes andM≥1 DL subframes may be associated with a single UL subframe. Theassociation is in the sense that HARQ-ACK information generated inresponse to reception of data TBs in M≥1 DL subframes is transmitted ina single UL subframe. This set of M≥1 DL subframes is commonly referredto as a bundling window. Denoting a DL subframe index by m=0, 1, . . . ,M−1, a number of CCEs for a PCFICH value of p (N₀=0) by N_(p), and afirst PDCCH CCE of a DL SA in subframe m by n_(CCE)(m), a PUCCH resourceindexing for HARQ-ACK signal transmission can be as described below.

A UE first selects a value p∈{0, 1, 2, 3} providing and thenN_(p)≤n_(CCE) (m)<N_(p+1) considersn_(PUCCH,m)=(M−m−1)×N_(p)+m×N_(p+1)+n_(CCE) (m)+N_(PUCCH) as a PUCCHresource available for HARQ-ACK signal transmission in response to a DLSA in DL subframe m, where N_(p)=max{0,└[N_(RB) ^(DL)×(N_(sc)^(RB)×p−4)]/36┘}, N_(PUCCH) is an offset informed to a UE by higherlayer signaling, N_(sc) ^(RB) is a number of sub-carriers and N_(RB)^(DL) is a number of PRBs in the DL operating BW.

HARQ-ACK information in a PUCCH may be conveyed with several methodsincluding HARQ-ACK time-domain bundling and HARQ-ACK multiplexing usingchannel selection (referring to a selection of a PUCCH resource from aset of available PUCCH resources). In both cases, HARQ-ACKspatial-domain bundling applies where a UE generates an ACK, only if itreceives all data TBs in a PDSCH correctly, and generates a NACKotherwise.

With HARQ-ACK time-domain bundling, a UE generates an ACK, only if itreceives all TBs in a bundling window correctly, and generates a NACKotherwise. Therefore, HARQ-ACK time-domain bundling results inunnecessary retransmissions as a NACK is sent even when the UE correctlyreceives some of the TBs in a bundling window.

With HARQ-ACK multiplexing using channel selection, a UE conveysHARQ-ACK information for each DL subframe in a bundling window byselecting a PUCCH resource from a set of possible resources and bymodulating the HARQ-ACK signal using QPSK modulation.

Table 2 describes HARQ-ACK multiplexing using channel selection for M=3in a TDD system with a single DL cell and a single UL cell.Specifically, a UE modulates a HARQ-ACK signal using the QPSKconstellation point and selects one of PUCCH resources n_(PUCCH) (0)n_(PUCCH) (1) or n_(PUCCH)(2) which are respectively determined by afirst CCE of a respective PDCCH conveying a DL SA in a respective first,second, or third DL subframe (if any).

Explicit DTX indication is possible by including a Downlink AssignmentIndex (DAI) Information Element (IE), which indicates an accumulativenumber of PDSCH transmission(s) to a UE (the DAI IE is a counter withina bundling window), in DCI formats conveying DL SAs.

TABLE 2 HARQ-ACK Multiplexing with Channel Selection for M = 3 DLSubframes Entry HARQ-ACK(0), HARQ-ACK(1), Number HARQ-ACK(2) n_(PUCCH)Constellation 1 ACK, ACK, ACK n_(PUCCH, 2) 1, 1 2 ACK, ACK, NACK/DTXn_(PUCCH,1) 1, 1 3 ACK, NACK/DTX, ACK n_(PUCCH,0) 1, 1 4 ACK, NACK/DTX,NACK/DTX n_(PUCCH,0) 0, 1 5 NACK/DTX, ACK, ACK n_(PUCCH,2) 1, 0 6NACK/DTX, ACK, NACK/DTX n_(PUCCH,1) 0, 0 7 NACK/DTX, NACK/DTX, ACKn_(PUCCH,2) 0, 0 8 DTX, DTX, NACK n_(PUCCH,2) 0, 1 9 DTX, NACK, NACK/DTXn_(PUCCH,1) 1, 0 10 NACK, NACK/DTX, NACK/DTX n_(PUCCH,0) 1, 0 11 DTX,DTX, DTX N/A N/A

When HARQ-ACK information is transmitted in a PUSCH, it is encodeddepending on a number of HARQ-ACK bits being conveyed. Assuming HARQ-ACKspatial-domain bundling, each HARQ-ACK bit conveys an outcome of eachPDSCH reception and is encoded as a binary ‘1’, if the respective TB(s)are correctly received (i.e., an ACK), and is encoded as a binary ‘0’,if the respective TB(s) are incorrectly received (i.e., a NACK).Therefore, an individual HARQ-ACK bit is conveyed for each PDSCHreception. When HARQ-ACK information consists of O=1 bit o₀ ^(ACK), itis encoded using repetition coding. When HARQ-ACK information consistsof O=2 bits [o₀ ^(ACK) o₁ ^(ACK)], it is encoded using a (3, 2) simplexcode, as described in Table 3 for Q_(m) data modulation bits, where o₂^(ACK)=(o₀ ^(ACK)+o₁ ^(ACK)) mod 2.

TABLE 3 Encoding for 1 and 2 HARQ-ACK Information Bits. Encoded Q_(m)HARQ-ACK - 1 bit Encoded HARQ-ACK - 2 bits 2 [o₀ ^(ACK) y] [o₀ ^(ACK) o₁^(ACK) o₂ ^(ACK) o₀ ^(ACK) o₁ ^(ACK) o₂ ^(ACK)] 4 [o₀ ^(ACK) y x x] [o₀^(ACK) o₁ ^(ACK) X X o₂ ^(ACK) o₀ ^(ACK) X X o₁ ^(ACK) o₂ ^(ACK)X X] 6[o₀ ^(ACK) y x x x x] [o₀ ^(ACK) o₁ ^(ACK) x x x x o₂ ^(ACK) o₀ ^(ACK) xx x x o₁ ^(ACK) o₂ ^(ACK)x x x x]

When HARQ-ACK information corresponds to a possible reception of morethan 2 PDSCHs (assuming HARQ-ACK spatial-domain bundling) and consistsof respective 3≤O^(ACK)≤11 bits, the coding may be by a (32, O^(ACK))Reed-Mueller (RM) block code. Denoting the HARQ-ACK information bits byo₀ ^(ACK) o₁ ^(ACK), . . . , o_(o) _(ACK) ⁻¹ ^(ACK) and the encodedHARQ-ACK bits by {tilde over (q)}₀ ^(ACK){tilde over (q)}₁ ^(ACK), . . ., {tilde over (q)}₃₁ ^(ACK),

${{\overset{\sim}{q}}_{i}^{ACK} = {\sum\limits_{n = 0}^{O - 1}{\left( {o_{n}^{ACK} \cdot M_{i,n}} \right){mod}\mspace{11mu} 2}}},$where M_(i,n) are basis sequences of an RM code and i=0, 1, . . . , 31.The output bit sequence q₀ ^(ACK), q₁ ^(ACK), q₂ ^(ACK), . . . , q_(Q)_(ACK−1) ^(ACK) is obtained by a circular repetition of the bit sequence{tilde over (q)}₀ ^(ACK){tilde over (q)}₁ ^(ACK), . . . , {tilde over(q)}₃₁ ^(ACK), such that the bit sequence length is equal to Q_(ACK)which is the total number of coded HARQ-ACK symbols in a PUSCH.

FIG. 5 is a block diagram illustrating a conventional transmitter fordata and HARQ-ACK in a PUSCH.

Referring to FIG. 5, the transmitter includes a data encoder 515, an RMencoder 520, a puncturer/inserter 530, a DFT unit 540, a sub-carriermapper 550, a selector 555, an IFFT unit 560, a CP inserter 570, and afilter 580 for time windowing. Data information bits 505 and HARQ-ACKinformation bits 510 are respectively provided to the data encoder 515and the RM encoder 520. For two HARQ-ACK information bits, a simplexencoder is used instead of the RM encoder 520. Encoded data bits aresubsequently punctured and replaced by encoded HARQ-ACK bits by thepuncturer/inserter 530. The result is then input to a DFT unit 540. Aselector 555 selects REs corresponding to the PUSCH transmission BW forsubcarrier mapping in the sub-carrier mapper 550, which are then inputto the IFFT unit 560. A CP is inserted by the CP inserter 570, and theCP inserted signal then passes through the filter 580 before beingtransmitted 590. Again, additional transmitter circuitry is notillustrated for conciseness. Also, the modulation process for thetransmitted bits is omitted for brevity.

FIG. 6 is a conventional block diagram illustrating a receiver block fordata and HARQ-ACK in a PUSCH.

Referring to FIG. 6, the receiver includes a filter 620 for timewindowing, a CP remover 630, an FFT unit 640, a sub-carrier de-mapper650, a selector 655, an Inverse DFT (IDFT) unit 660, a de-multiplexer670, a data decoder 680, and an RM decoder 685. After an antenna (notshown) receives a Radio-Frequency (RF) analog signal and furtherprocessing units (not shown) convert the analog signal to a digitalsignal 610, the digital signal 610 passes through the filter 620 and theCP removal unit 630. The output of the CP removal unit 630 is providedto the FFT unit 640, and a selector 655 controls the sub-carrierde-mapper 650 to select the REs used by the transmitter. The obtainedvalues are provided to the IDFT unit 660 and the de-multiplexer 670,which outputs coded data bits. that the coded data bits are thenprovided to the data decoder 680 and the coded HARQ-ACK bits are thenprovided to the RM decoder 685 to respectively output data informationbits 690 and HARQ-ACK information bits 695. For two HARQ-ACK informationbits, a simplex decoder is used instead of the RM decoder 685. Similarto the transmitter illustrated in FIG. 5, receiver functionalities suchas channel estimation, demodulation, and decoding are not illustrated inFIG. 6 for brevity.

In order to increase the supportable data rates to a UE, a NodeB canconfigure multiple cells to a UE in both a DL and a UL to effectivelyprovide higher operating BWs. For example, to support communication over40 MHz, two 20 MHz cells can be configured to a UE. A UE is alwaysconfigured a DL cell and a UL cell to maintain communication and eachsuch cell is referred to as Primary cell (Pcell). Additional cells a UEmay be configured are referred to as Secondary cells (Scells).

A transmission of HARQ-ACK information can be in a PUCCH of the ULPcell. For HARQ-ACK multiplexing using channel selection, a separatePUCCH resource is assigned in a UL Pcell for HARQ-ACK signaltransmission in response to a PDSCH reception in each subframe of abundling window and each DL cell.

For two configured cells and a bundling window size of M>1 DL subframes,denoting PUCCH resources associated with reception of PDSCH(s) on the DLPcell by n_(PUCCH,0) and n_(PUCCH,1) and PUCCH resources associated withreception of PDSCH(s) on the Scell and by HARQ-ACK(j), 0≤j≤M−1, byn_(PUCCH,2) and n_(PUCCH,3), the ACK/NACK/DTX response for a PDSCH withcorresponding DAI value in a PDCCH equal to ‘j+1’, a UE performs channelselection according to Table 4 for M=3 and Table 5 for M=4 and transmitsa HARQ-ACK signal using QPSK modulation {b(0),b(1)} on PUCCH resourcen_(PUCCH). For the last state in Table 4 and the last two states inTable 5, there is no transmission in a PUCCH, as a UE cannot determine avalid PUCCH resource. The value ‘any’ can be either ‘ACK’ or ‘NACK/DTX’.

TABLE 4 HARQ-ACK Multiplexing with Channel Selection for M = 3 DLSubframes and 2 Configured Cells. Primary Cell Secondary CellHARQ-ACK(0), HARQ-ACK(0), HARQ-ACK(1), HARQ-ACK(1), ResourceConstellation HARQ-ACK(2) HARQ-ACK(2) n_(PUCCH) b(0), b(1) ACK, ACK, ACKACK, ACK, ACK n_(PUCCH,1) 1, 1 ACK, ACK, ACK, ACK, ACK n_(PUCCH,1) 0, 0NACK/DTX ACK, NACK/DTX, any ACK, ACK, ACK n_(PUCCH,3) 1, 1 NACK/DTX,any, any ACK, ACK, ACK n_(PUCCH,3) 0, 1 ACK, ACK, ACK ACK, ACK,n_(PUCCH,0) 1, 0 NACK/DTX ACK, ACK, ACK, ACK, n_(PUCCH,3) 1, 0 NACK/DTXNACK/DTX ACK, NACK/DTX, any ACK, ACK, n_(PUCCH,0) 0, 1 NACK/DTXNACK/DTX, any, any ACK, ACK, n_(PUCCH,3) 0, 0 NACK/DTX ACK, ACK, ACKACK, NACK/DTX, n_(PUCCH,2) 1, 1 any ACK, ACK, ACK, NACK/DTX, n_(PUCCH,2)0, 1 NACK/DTX any ACK, NACK/DTX, any ACK, NACK/DTX, n_(PUCCH,2) 1, 0 anyNACK/DTX, any, any ACK, NACK/DTX, n_(PUCCH,2) 0, 0 any ACK, ACK, ACKNACK/DTX, any, n_(PUCCH,1) 1, 0 any ACK, ACK, NACK/DTX, any, n_(PUCCH,1)0, 1 NACK/DTX any ACK, NACK/DTX, any NACK/DTX, any, n_(PUCCH,0) 1, 1 anyNACK, any, any NACK/DTX, any, n_(PUCCH,0) 0, 0 any DTX, any, anyNACK/DTX, any, No Transmission any

TABLE 5 HARQ-ACK Multiplexing with Channel Selection for M = 4 DLSubframes and 2 Configured Cells. Primary Cell Secondary CellHARQ-ACK(0), HARQ- HARQ-ACK(0), HARQ- ACK(1), HARQ-ACK(2), ACK(1),HARQ-ACK(2), Resource Constellation HARQ-ACK(3) HARQ-ACK(3) n_(PUCCH)b(0), b(1) ACK, ACK, ACK, ACK, ACK, ACK, n_(PUCCH,1) 1, 1 NACK/DTXNACK/DTX ACK, ACK, NACK/DTX, ACK, ACK, ACK, n_(PUCCH,1) 0, 0 anyNACK/DTX ACK, DTX, DTX, DTX ACK, ACK, ACK, n_(PUCCH,3) 1, 1 NACK/DTXACK, ACK, ACK, ACK ACK, ACK, ACK, n_(PUCCH,3) 1, 1 NACK/DTX NACK/DTX,any, any, any ACK, ACK, ACK, n_(PUCCH,3) 0, 1 NACK/DTX {ACK, NACK/DTX,any, ACK, ACK, ACK, n_(PUCCH,3) 0, 1 any}, except for {ACK, DTX,NACK/DTX DTX, DTX} ACK, ACK, ACK, ACK, ACK, NACK/DTX, n_(PUCCH,0) 1, 0NACK/DTX any ACK, ACK, NACK/DTX, ACK, ACK, NACK/DTX, n_(PUCCH,3) 1, 0any any ACK, DTX, DTX, DTX ACK, ACK, NACK/DTX, n_(PUCCH,0) 0, 1 any ACK,ACK, ACK, ACK ACK, ACK, NACK/DTX, n_(PUCCH,0) 0, 1 any NACK/DTX, any,any, any ACK, ACK, NACK/DTX, n_(PUCCH,3) 0, 0 any {ACK, NACK/DTX, any,ACK, ACK, NACK/DTX, n_(PUCCH,3) 0, 0 any}, except for {ACK, DTX, anyDTX, DTX} ACK, ACK, ACK, ACK, DTX, DTX, DTX n_(PUCCH,2) 1, 1 NACK/DTXACK, ACK, ACK, ACK, ACK, ACK, ACK n_(PUCCH,2) 1, 1 NACK/DTX ACK, ACK,NACK/DTX, ACK, DTX, DTX, DTX n_(PUCCH,2) 0, 1 any ACK, ACK, NACK/DTX,ACK, ACK, ACK, ACK n_(PUCCH,2) 0, 1 any ACK, DTX, DTX, DTX ACK, DTX,DTX, DTX n_(PUCCH,2) 1, 0 ACK, DTX, DTX, DTX ACK, ACK, ACK, ACKn_(PUCCH,2) 1, 0 ACK, ACK, ACK, ACK ACK, DTX, DTX, DTX n_(PUCCH,2) 1, 0ACK, ACK, ACK, ACK ACK, ACK, ACK, ACK n_(PUCCH,2) 1, 0 NACK/DTX, any,any, any ACK, DTX, DTX, DTX n_(PUCCH,2) 0, 0 NACK/DTX, any, any, anyACK, ACK, ACK, ACK n_(PUCCH,2) 0, 0 {ACK, NACK/DTX, any, ACK, DTX, DTX,DTX n_(PUCCH,2) 0, 0 any}, except for {ACK, DTX, DTX, DTX} {ACK,NACK/DTX, any, ACK, ACK, ACK, ACK n_(PUCCH,2) 0, 0 any}, except for{ACK, DTX, DTX, DTX} ACK, ACK, ACK, NACK/DTX, any, any, any n_(PUCCH,1)1, 0 NACK/DTX ACK, ACK, ACK, {ACK, NACK/DTX, any, n_(PUCCH,1) 1, 0NACK/DTX any}, except for {ACK, DTX, DTX, DTX} ACK, ACK, NACK/DTX,NACK/DTX, any, any, any n_(PUCCH,1) 0, 1 any ACK, ACK, NACK/DTX, {ACK,NACK/DTX, any, n_(PUCCH,1) 0, 1 any any}, except for {ACK, DTX, DTX,DTX} ACK, DTX, DTX, DTX NACK/DTX, any, any, any n_(PUCCH,0) 1, 1 ACK,DTX, DTX, DTX {ACK, NACK/DTX, any, n_(PUCCH,0) 1, 1 any}, except for{ACK, DTX, DTX, DTX} ACK, ACK, ACK, ACK NACK/DTX, any, any, anyn_(PUCCH,0) 1, 1 ACK, ACK, ACK, ACK {ACK, NACK/DTX, any, n_(PUCCH,0) 1,1 any}, except for {ACK, DTX, DTX, DTX} NACK, any, any, any NACK/DTX,any, any, any n_(PUCCH,0) 0, 0 NACK, any, any, any {ACK, NACK/DTX, any,n_(PUCCH,0) 0, 0 any}, except for {ACK, DTX, DTX, DTX} {ACK, NACK/DTX,any, NACK/DTX, any, any, any n_(PUCCH,0) 0, 0 any}, except for {ACK,DTX, DTX, DTX} {ACK, NACK/DTX, any, {ACK, NACK/DTX, any, n_(PUCCH,0) 0,0 any}, except for {ACK, DTX, any}, except for {ACK, DTX, DTX} DTX, DTX,DTX} DTX, any, any, any NACK/DTX, any, any, any No Transmission DTX,any, any, any {ACK, NACK/DTX, any, No Transmission any}, except for{ACK, DTX, DTX, DTX}

For a single-cell operation, HARQ-ACK multiplexing with channelselection conveys a number of HARQ-ACK states in a PUCCH, as describedin the example of Table 3 for M=3, while HARQ-ACK transmission in aPUSCH conveys an individual information bit for each DL subframe in abundling window (or for a number of DL subframes specified by a DAI IEin a UL SA scheduling a PUSCH transmission, if any). Therefore, amaximum of M HARQ-ACK information bits are conveyed. However, if a sameapproach for HARQ-ACK transmission in a PUSCH were to be followed formulti-cell (DL CA: Down Link Carrier Aggregation) operation, the maximumnumber of HARQ-ACK information bits would linearly scale with the numberof configured cells to a UE. However, increasing the number of HARQ-ACKinformation bits in a PUSCH for UEs configured HARQ-ACK multiplexingwith channel selection in a PUCCH may result in a failure to provide therequired HARQ-ACK reception reliability and will often lead to differentoperations depending on the channel, PUCCH, or PUSCH, used to transmitthe HARQ-ACK information.

SUMMARY OF THE INVENTION

Accordingly, the present invention has been designed to solve at leastthe aforementioned limitations and problems in the prior art and toprovide at least the advantages described below.

An aspect of the present invention is to provide a method fortransmitting acknowledgement information efficiently in response to dataTransport Blocks (TBs) received in one or more downlink data channels ina Time Division Duplex (TDD) communication system.

Another aspect of the present invention is to provide a method for a UEconfigured with two or more cells in a TDD system to transmit HARQ-ACKinformation in a PUSCH, when it transmits HARQ-ACK information usingmultiplexing with channel selection in a PUCCH.

Another aspect of the present invention is to provide a mapping betweenHARQ-ACK bits transmitted in a PUSCH and the information that these bitsrepresent.

Another aspect of the present invention is to provide a sameunderstanding between a NodeB and a UE of the information represented byHARQ-ACK bits a UE transmits in a PUSCH.

In accordance with an aspect of the present invention, a method isprovided for transmitting acknowledgement information by a userequipment (UE) in a communication system. The method includes receivingone or more data transport blocks (TBs) in one or more downlink datachannels over transmission time intervals (TTIs); obtainingacknowledgement information comprising four acknowledgement informationbits {0, 0, 0, 0}, jointly representing a state of reception results fora plurality of data TBs, wherein a number of the plurality of data TBsis greater than a number of the acknowledgement information bits, the UEis configured for reception of the one or more downlink data channelsfrom two cells, and a number of the TTIs is three or four; Reed-Mueller(RM) encoding the acknowledgement information bits; and transmitting theRM encoded acknowledgement information bits on an uplink data channel.One of the state of reception results is represented as {NACK, any, any,any} and {NACK/DTX, any, any, any} for a first cell and a second cell ofthe two cells, respectively, or is represented as {NACK, any, any} and{NACK/DTX, any, any} for the first cell and the second cell,respectively, by the acknowledgement information bits {0, 0, 0, 0}. The‘NACK’ indicates a negative acknowledgement (ACK), the ‘DTX’ indicatesdiscontinuous transmission, and the ‘any’ indicates either an ACK or aNACK/DTX.

In accordance with another aspect of the present invention, a userequipment (UE) is provided for transmitting acknowledgement informationin a communication system. The UE includes a receiver configured toreceive one or more data transport blocks (TBs) in one or more downlinkdata channels over transmission time intervals (TTIs); a controllerconfigured to obtain acknowledgement information comprising fouracknowledgement information bits {0, 0, 0, 0}, jointly representing astate of reception results for a plurality of data TBs, wherein a numberof the plurality of data TBs is greater than a number of theacknowledgement information bits, the UE is configured for reception ofthe one or more downlink data channels from two cells, and a number ofthe TTIs is three or four; a Reed-Mueller (RM) encoder configured to RMencode the acknowledgement information bits; and a transmitterconfigured to transmit the RM encoded acknowledgement information bitson an uplink data channel. One of the state of reception results isrepresented as {NACK, any, any, any} and {NACK/DTX, any, any, any} for afirst cell and a second cell of the two cells, respectively, orrepresented as {NACK, any, any} and {NACK/DTX, any, any} for the firstcell and the second cell, respectively, by the acknowledgementinformation bits {0, 0, 0, 0}. The ‘NACK’ indicates a negativeacknowledgement (ACK), the ‘DTX’ indicates discontinuous transmission,and the ‘any’ indicates either an ACK or a NACK/DTX.

In accordance with another aspect of the present invention, a method isprovided for receiving acknowledgement information by a base station ina communication system. The method includes transmitting one or moredata transport blocks (TBs) in one or more downlink data channels overtransmission time intervals (TTIs); receiving, on an uplink data channelfrom a user equipment (UE), acknowledgement information comprising fouracknowledgement information bits {0, 0, 0, 0}, jointly representing astate of transmission results for the one or more data TBs, wherein anumber of the data TBs is greater than a number of the acknowledgementinformation bits, the UE is configured for reception of the one or moredownlink data channels from two cells, and a number of the TTIs is threeor four; and Reed-Mueller (RM) decoding the received acknowledgementinformation bits. One of the state of transmission results isrepresented as {NACK, any, any, any} and {NACK/DTX, any, any, any} for afirst cell and a second cell of the two cells, respectively, orrepresented as {NACK, any, any} and {NACK/DTX, any, any} for the firstcell and the second cell, respectively, by the acknowledgementinformation bits {0, 0, 0, 0}. The ‘NACK’ indicates a negativeacknowledgement (ACK), the ‘DTX’ indicates discontinuous transmission,and the ‘any’ indicates either an ACK or a NACK/DTX.

In accordance with another aspect of the present invention, a basestation is provided for receiving acknowledgement information in acommunication system. The base station includes a transmitter configuredto transmit one or more data transport blocks (TBs) in one or moredownlink data channels over transmission time intervals (TTIs); areceiver configured to receive, on an uplink data channel from a userequipment (UE), acknowledgement information comprising fouracknowledgement information bits {0, 0, 0, 0}, jointly representing astate of transmission results for the one or more data TBs, wherein anumber of the data TBs is greater than a number of the acknowledgementinformation bits, the UE is configured for reception of the one or moredownlink data channels from two cells, and a number of the TTIs is threeor four; and a Reed-Mueller (RM) decoder configured to RM decode thereceived acknowledgement information bits. One of the state oftransmission results is represented as {NACK, any, any, any} and{NACK/DTX, any, any, any} for a first cell and a second cell of the twocells, respectively, or represented as {NACK, any, any} and {NACK/DTX,any, any} for the first cell and the second cell, respectively, by theacknowledgement information bits {0, 0, 0, 0}. The ‘NACK’ indicates anegative acknowledgement (ACK), the ‘DTX’ indicates discontinuoustransmission, and the ‘any’ indicates either an ACK or a NACK/DTX.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects, features, and advantages of the presentinvention will be more apparent from the following detailed descriptiontaken in conjunction with the accompanying drawings, in which:

FIG. 1 is a diagram illustrating a conventional TTI for a PUSCH or for aPUCCH;

FIG. 2 is a diagram illustrating a conventional HARQ-ACK transmissionstructure in a PUCCH subframe slot;

FIG. 3 is a block diagram illustrating a conventional transmitter for aPUCCH;

FIG. 4 is a block diagram illustrating a conventional receiver for aPUCCH;

FIG. 5 is a block diagram illustrating a conventional transmitter fordata and HARQ-ACK in a PUSCH;

FIG. 6 is a block diagram illustrating a conventional receiver for dataand HARQ-ACK in a PUSCH;

FIG. 7 is a flowchart illustrating a method of identifying HARQ-ACK bitrepresentation depending on a number of configured cells and on a valueof a bundling window, according to an embodiment of the presentinvention;

FIG. 8 is a flowchart illustrating an encoding and decoding process ofHARQ-ACK information for a UE configured with two cells, depending on avalue of a bundling window, according to an embodiment of the presentinvention;

FIG. 9 is a flowchart illustrating an encoding and decoding process ofHARQ-ACK states, depending on whether a transmission is in a PUCCH or ina PUSCH, for M=3 or M=4 subframes, according to an embodiment of thepresent invention;

FIG. 10 is a block diagram illustrating a transmitter for transmittingdata and HARQ-ACK information in a PUSCH, according to an embodiment ofthe present invention; and

FIG. 11 is a block diagram illustrating a receiver for receiving dataand HARQ-ACK information in a PUSCH, according to an embodiment of thepresent invention.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

Various embodiments of the present invention will now be described morefully hereinafter with reference to the accompanying drawings. Thispresent invention may, however, be embodied in many different forms andshould not be construed as limited to the embodiments set forth herein.Rather, these embodiments are provided so that this disclosure will bethorough and complete and will fully convey the scope of the presentinvention to those skilled in the art.

Additionally, although embodiments of the present invention will bedescribed below with reference to DFT-spread OFDM transmission, thepresent invention is also applicable to Frequency Division Multiplexing(FDM) transmissions, such as Single-Carrier Frequency Division MultipleAccess (SC-FDMA) and OFDM.

In the following descriptions for HARQ-ACK transmission in a PUSCH, thevalue of M (i.e., a number of PDSCHs for which a UE provides HARQ-ACKinformation or a size of bundling window or a number of TTIs) can eitherbe fixed, as defined by a bundling window size for a particularconfiguration of a TDD system, or be variable, as defined by a value ofa DAI IE in a UL SA conveyed by a PDCCH scheduling a PUSCH transmission,if such a UL SA exists. Further, although for simplicity is thedescriptions assume that HARQ-ACK information is generated in responseto a PDSCH reception, the HARQ-ACK information may also be generated inresponse to a PDCCH that does not schedule a PDSCH reception, butinstead indicates a release of a Semi-Persistently Scheduled (SPS)PDSCH.

In accordance with an embodiment of the present invention, a UE isconfigured with two DL cells (the Pcell and a Scell) in a TDD system andmapping of HARQ-ACK states is performed as shown in Tables 4 and 5 (forM=3 and M=4, respectively) to input bits of an RM code used for encodingHARQ-ACK information in a PUSCH. This mapping is performed under theconstraint that the number of HARQ-ACK information bits input to an RMcode is limited to four, as HARQ-ACK multiplexing with channel selectionin a PUCCH is assumed to be supported for only up to four HARQ-ACKinformation bits conveying different HARQ-ACK states. That is, two bitsare conveyed through the selection of a PUCCH resource among fouravailable resources, and another two bits are conveyed through a QPSKmodulated signal by the respective constellation points.

Unlike conventional HARQ-ACK transmission in a PUSCH, where eachHARQ-ACK information bit represents the outcome of respective data TBreception(s) in a PDSCH, in accordance with an embodiment of the presentinvention, the mapping of HARQ-ACK information to four input bits of anRM encoder for the above operating scenario includes HARQ-ACK states (aHARQ-ACK state is a set of correct or incorrect detection outcomes fordata TBs) conveying combinations for values of HARQ-ACK bits as shown inTables 4 and 5. Therefore, all four HARQ-ACK information bits arejointly considered and an individual HARQ-ACK bit does not have arespective individual interpretation (as it does not indicate anindividual correct or incorrect detection outcome for data TBs). Thisalternative representation is used because the four input bits to an RMcode do not suffice to represent all possible combinations for theindividual outcomes of data TB reception(s) in each PDSCH in two cellsfor M=3 or M=4 (i.e., 6 or 8 bits, respectively, would be needed).

Conversely, for M=2, four input bits to an RM encoder can provideindividual HARQ-ACK information about the outcome of data TBreception(s) in a PDSCH for each respective subframe of a bundlingwindow and for each of the two cells (Pcell and Scell). For example, twoof the four bits can be used to represent HARQ-ACK information for thePcell and the other two can be used to represent HARQ-ACK informationfor the Scell with the first of the two bits corresponding to the firstof the M=2 subframes and the second of the two bits corresponding to thesecond of the M=2 subframes. For M=1, two input bits to an RM encodercan provide individual HARQ-ACK information about the outcome a PDSCHreception in the Pcell and the Scell, respectively.

FIG. 7 is a flowchart illustrating a method of identifying HARQ-ACK bitrepresentation depending on a number of configured cells and on a valueof a bundling window, according to an embodiment of the presentinvention.

Referring to FIG. 7, for a PUSCH transmitter and a PUSCH receiver, themeaning of HARQ-ACK information bits in a PUSCH depends on whether a UEis configured one or two cells in step 710. If a UE is configured onecell, in step 720, the PUSCH transmitter or receiver determines thateach HARQ-ACK information bit represents an outcome (e.g., ACK forbinary ‘1’ or NACK/DTX for binary ‘0’) for a reception of TB(s) in acorresponding PDSCH, regardless of the value of M. This assumes thatHARQ-ACK spatial-domain bundling applies if a PDSCH conveys multipleTBs, that a DTX state and a NACK state are jointly represented, and theexplicit DTX feedback is not supported in a PUSCH; however, the reversemay also apply.

If a UE is configured two cells, the representation of HARQ-ACKinformation bits depends on the value of M in step 730. If M is smallerthan or equal to 2, in step 740, the PUSCH transmitter or receiverdetermines that each HARQ-ACK information bit again represents anoutcome (ACK for binary ‘1’ or NACK/DTX for binary ‘0’) for a receptionof TB(s) in a corresponding PDSCH. However, if M is larger than 2, instep 750, the PUSCH transmitter or receiver determines that eachHARQ-ACK information bit does not provide any information on its own andall HARQ-ACK information bits are jointly considered to indicate aHARQ-ACK state (set of outcomes for correct or incorrect detection ofdata TB(s) in respective PDSCH(s)) corresponding to both cells and allPDSCHs for which HARQ-ACK information is provided by a UE.

In accordance with another embodiment of the present invention, HARQ-ACKstates, as represented in Tables 4 and 5, are transmitted in a PUCCHusing channel selection, by the four input bits {o₀ ^(ACK) o₁ ^(ACK) o₂^(ACK) o₃ ^(ACK)} to an RM encoder for transmission in a PUSCH. Thisrepresentation is obtained by one-to-one mapping of a PUCCH resource anda constellation point of a QPSK modulation of a HARQ-ACK signal in aPUCCH to four input bits {o₀ ^(ACK) o₁ ^(ACK) o₂ ^(ACK) o₃ ^(ACK)} of anRM code in a PUSCH, e.g., as shown in Table 6 for M=3 and in Table 7 forM=4.

For example, the first four PUCCH resources {n_(PUCCH,0), n_(PUCCH,1),n_(PUCCH,2), n_(PUCCH,3)} may be represented by RM input bits {o₀ ^(ACK)o₁ ^(ACK)} and the four QPSK constellation points {(0,0), (0,1), (1,0),(1,1)} in a PUCCH may be represented by RM input bits {o₂ ^(ACK) o₃^(ACK)}. In general, any representation of any two RM input bits forfour PUCCH resources and of the other two RM input bits for the QPSKconstellation points in a PUCCH may be used.

TABLE 6 Mapping of HARQ-ACK States to Input Bits of the RM Code for M =3. Primary Cell Secondary Cell HARQ-ACK(0), HARQ-ACK(0), RM Code InputHARQ-ACK(1), HARQ-ACK(1), Resource Constellation Bits HARQ-ACK(2)HARQ-ACK(2) n_(PUCCH) b(0), b(1) {o₀ ^(ACK) o₁ ^(ACK) o₂ ^(ACK) o₃^(ACK)} ACK, ACK, ACK ACK, ACK, ACK n_(PUCCH,1) 1, 1 0, 1, 1, 1 ACK,ACK, ACK, ACK, ACK n_(PUCCH,1) 0, 0 0, 1, 0, 0 NACK/DTX ACK, ACK, ACK,ACK n_(PUCCH,3) 1, 1 1, 1, 1, 1 NACK/DTX, any NACK/DTX, any, ACK, ACK,ACK n_(PUCCH,3) 0, 1 1, 1, 0, 1 any ACK, ACK, ACK ACK, ACK, n_(PUCCH,0)1, 0 0, 0, 1, 0 NACK/DTX ACK, ACK, ACK, ACK, n_(PUCCH,3) 1, 0 1, 1, 1, 0NACK/DTX NACK/DTX ACK, ACK, ACK, n_(PUCCH,0) 0, 1 0, 0, 0, 1 NACK/DTX,any NACK/DTX NACK/DTX, any, ACK, ACK, n_(PUCCH,3) 0, 0 1, 1, 0, 0 anyNACK/DTX ACK, ACK, ACK ACK, n_(PUCCH,2) 1, 1 1, 0, 1, 1 NACK/DTX, anyACK, ACK, ACK, n_(PUCCH,2) 0, 1 1, 0, 0, 1 NACK/DTX NACK/DTX, any ACK,ACK, n_(PUCCH,2) 1, 0 1, 0, 1, 0 NACK/DTX, any NACK/DTX, any NACK/DTX,any, ACK, n_(PUCCH,2) 0, 0 1, 0, 0, 0 any NACK/DTX, any ACK, ACK, ACKNACK/DTX, any, n_(PUCCH,1) 1, 0 0, 1, 1, 0 any ACK, ACK, NACK/DTX, any,n_(PUCCH,1) 0, 1 0, 1, 0, 1 NACK/DTX any ACK, NACK/DTX, any, n_(PUCCH,0)1, 1 0, 0, 1, 1 NACK/DTX, any any NACK, any, any NACK/DTX, any,n_(PUCCH,0) 0, 0 0, 0, 0, 0 any DTX, any, any NACK/DTX, any, NoTransmission 0, 0, 0, 0 any

TABLE 7 Mapping of HARQ-ACK States to Input Bits of the RM Code for M =4. Primary Cell Secondary Cell HARQ-ACK(0), HARQ-ACK(0), HARQ-ACK(1),HARQ-ACK(1), RM Code Input HARQ-ACK(2), HARQ-ACK(2), ResourceConstellation Bits HARQ-ACK(3) HARQ-ACK(3) n_(PUCCH) b(0), b(1) {o₀^(ACK) o₁ ^(ACK) o₂ ^(ACK) o₃ ^(ACK)} ACK, ACK, ACK, ACK, ACK, ACK,n_(PUCCH,1) 1, 1 0, 1, 1, 1 NACK/DTX NACK/DTX ACK, ACK, ACK, ACK, ACK,n_(PUCCH,1) 0, 0 0, 1, 0, 0 NACK/DTX, any NACK/DTX ACK, DTX, DTX, ACK,ACK, ACK, n_(PUCCH,3) 1, 1 1, 1, 1, 1 DTX NACK/DTX ACK, ACK, ACK, ACK,ACK, ACK, n_(PUCCH,3) 1, 1 1, 1, 1, 1 ACK NACK/DTX NACK/DTX, any, any,ACK, ACK, ACK, n_(PUCCH,3) 0, 1 1, 1, 0, 1 any NACK/DTX {ACK, NACK/DTX,ACK, ACK, ACK, n_(PUCCH,3) 0, 1 1, 1, 0, 1 any, any}, except forNACK/DTX {ACK, DTX, DTX, DTX} ACK, ACK, ACK, ACK, ACK, n_(PUCCH,0) 1, 00, 0, 1, 0 NACK/DTX NACK/DTX, any ACK, ACK, ACK, ACK, n_(PUCCH,3) 1, 01, 1, 1, 0 NACK/DTX, any NACK/DTX, any ACK, DTX, DTX, ACK, ACK,n_(PUCCH,0) 0, 1 0, 0, 0, 1 DTX NACK/DTX, any ACK, ACK, ACK, ACK, ACK,n_(PUCCH,0) 0, 1 0, 0, 0, 1 ACK NACK/DTX, any NACK/DTX, any, any, ACK,ACK, n_(PUCCH,3) 0, 0 1, 1, 0, 0 any NACK/DTX, any {ACK, NACK/DTX, ACK,ACK, n_(PUCCH,3) 0, 0 1, 1, 0, 0 any, any}, except for NACK/DTX, any{ACK, DTX, DTX, DTX} ACK, ACK, ACK, ACK, DTX, DTX, n_(PUCCH,2) 1, 1 1,0, 1, 1 NACK/DTX DTX ACK, ACK, ACK, ACK, ACK, ACK, n_(PUCCH,2) 1, 1 1,0, 1, 1 NACK/DTX ACK ACK, ACK, ACK, DTX, DTX, n_(PUCCH,2) 0, 1 1, 0, 0,1 NACK/DTX, any DTX ACK, ACK, ACK, ACK, ACK, n_(PUCCH,2) 0, 1 1, 0, 0, 1NACK/DTX, any ACK ACK, DTX, DTX, ACK, DTX, DTX, n_(PUCCH,2) 1, 0 1, 0,1, 0 DTX DTX ACK, DTX, DTX, ACK, ACK, ACK, n_(PUCCH,2) 1, 0 1, 0, 1, 0DTX ACK ACK, ACK, ACK, ACK, DTX, DTX, n_(PUCCH,2) 1, 0 1, 0, 1, 0 ACKDTX ACK, ACK, ACK, ACK, ACK, ACK, n_(PUCCH,2) 1, 0 1, 0, 1, 0 ACK ACKNACK/DTX, any, any, ACK, DTX, DTX, n_(PUCCH,2) 0, 0 1, 0, 0, 0 any DTXNACK/DTX, any, any, ACK, ACK, ACK, n_(PUCCH,2) 0, 0 1, 0, 0, 0 any ACK{ACK, NACK/DTX, ACK, DTX, DTX, n_(PUCCH,2) 0, 0 1, 0, 0, 0 any, any},except for DTX {ACK, DTX, DTX, DTX} {ACK, NACK/DTX, ACK, ACK, ACK,n_(PUCCH,2) 0, 0 1, 0, 0, 0 any, any}, except for ACK {ACK, DTX, DTX,DTX} ACK, ACK, ACK, NACK/DTX, any, n_(PUCCH,1) 1, 0 0, 1, 1, 0 NACK/DTXany, any ACK, ACK, ACK, {ACK, NACK/DTX, n_(PUCCH,1) 0, 1 0, 1, 1, 0NACK/DTX any, any}, except for {ACK, DTX, DTX, DTX} ACK, ACK, NACK/DTX,any, n_(PUCCH,1) 0, 1 0, 1, 0, 1 NACK/DTX, any any, any ACK, ACK, {ACK,NACK/DTX, n_(PUCCH,1) 0, 1 0, 1, 0, 1 NACK/DTX, any any, any}, exceptfor {ACK, DTX, DTX, DTX} ACK, DTX, DTX, NACK/DTX, any, n_(PUCCH,0) 1, 10, 0, 1, 1 DTX any, any ACK, DTX, DTX, {ACK, NACK/DTX, n_(PUCCH,0) 1, 10, 0, 1, 1 DTX any, any}, except for {ACK, DTX, DTX, DTX} ACK, ACK, ACK,NACK/DTX, any, n_(PUCCH,0) 1, 1 0, 0, 1, 1 ACK any, any ACK, ACK, ACK,{ACK, NACK/DTX, n_(PUCCH,0) 1, 1 0, 0, 1, 1 ACK any, any}, except for{ACK, DTX, DTX, DTX} NACK, any, any, any NACK/DTX, any, n_(PUCCH,0) 0, 00, 0, 0, 0 any, any NACK, any, any, any {ACK, NACK/DTX, n_(PUCCH,0) 0, 00, 0, 0, 0 any, any}, except for {ACK, DTX, DTX, DTX} {ACK, NACK/DTX,NACK/DTX, any, n_(PUCCH,0) 0, 0 0, 0, 0, 0 any, any}, except for any,any {ACK, DTX, DTX, DTX} {ACK, NACK/DTX, {ACK, NACK/DTX, n_(PUCCH,0) 0,0 0, 0, 0, 0 any, any}, except for any, any}, except for {ACK, DTX, DTX,{ACK, DTX, DTX, DTX} DTX} DTX, any, any, any NACK/DTX, any, NoTransmission 0, 0, 0, 0 any, any DTX, any, any, any {ACK, NACK/DTX, NoTransmission 0, 0, 0, 0 any, any}, except for {ACK, DTX, DTX, DTX}

Conversely, the representation of HARQ-ACK states to four input bits {o₀^(ACK) o₁ ^(ACK) o₂ ^(ACK) o₃ ^(ACK)} of an RM encoder for M=2 isobtained as shown in Table 8 below. Each individual HARQ-ACK bit nowprovides individual information with a binary ‘1’ representing an ‘ACK’and a binary ‘0’ representing a ‘NACK/DTX’ for a corresponding PDSCHreception. There is no link between the four input bits {o₀ ^(ACK) o₁^(ACK) o₂ ^(ACK) o₃ ^(ACK)} of an RM code for HARQ-ACK transmission in aPUSCH and the PUCCH resources or the constellation point of a QPSKmodulated signal for HARQ-ACK in a PUCCH. Similar observations apply forthe representation of HARQ-ACK states to the two input bits {o₀ ^(ACK)o₁ ^(ACK)} of a simplex (3, 2) code for M=1, which is obtained as shownin Table 9.

TABLE 8 Mapping of HARQ-ACK States to Input Bits of the RM Code for M =2. Primary Cell Secondary Cell RM Code Input HARQ-ACK(0), HARQ-HARQ-ACK(0), HARQ- Bits ACK(1) ACK(1) {o₀ ^(ACK) o₁ ^(ACK) o₂ ^(ACK) o₃^(ACK)} ACK, ACK ACK, ACK 1, 1, 1, 1 ACK, NACK/DTX ACK, ACK 1, 0, 1, 1NACK/DTX, ACK ACK, ACK 0, 1, 1, 1 NACK/DTX, NACK/DTX ACK, ACK 0, 0, 1, 1ACK, ACK ACK, NACK/DTX 1, 1, 1, 0 ACK, NACK/DTX ACK, NACK/DTX 1, 0, 1, 0NACK/DTX, ACK ACK, NACK/DTX 0, 1, 1, 0 NACK/DTX, NACK/DTX ACK, NACK/DTX0, 0, 1, 0 ACK, ACK NACK/DTX, ACK 1, 1, 0, 1 ACK, NACK/DTX NACK/DTX, ACK1, 0, 0, 1 NACK/DTX, ACK NACK/DTX, ACK 0, 1, 0, 1 NACK/DTX, NACK/DTXNACK/DTX, ACK 0, 0, 0, 1 ACK, ACK NACK/DTX, NACK/DTX 1, 1, 0, 0 ACK,NACK/DTX NACK/DTX, NACK/DTX 1, 0, 0, 0 NACK/DTX, ACK NACK/DTX, NACK/DTX0, 1, 0, 0 NACK/DTX, NACK/DTX NACK/DTX, NACK/DTX 0, 0, 0, 0

TABLE 9 Mapping of HARQ-ACK States to Input Bits of the Simplex Code form = 1. Simplex Code Input Primary Cell Secondary Cell Bits HARQ-ACK(0)HARQ-ACK(0) {o₀ ^(ACK) o₁ ^(ACK)} ACK ACK 1, 1 NACK/DTX ACK 0, 1 ACKNACK/DTX 1, 0 NACK/DTX NACK/DTX 0, 0

FIG. 8 illustrates encoding and decoding of HARQ-ACK information for aUE configured with two cells depending on a value of a bundling window,according to an embodiment of the present invention.

Referring to FIG. 8, the encoding and decoding for a UE configured withtwo cells and for a PUSCH transmitter and a PUSCH receiver,respectively, depends on a value of M in step 810. If M is less thantwo, in step 820, each HARQ-ACK information bit represents an outcome(e.g., ACK or NACK/DTX) of a respective PDSCH reception. However, if Mis greater than two, in step 830, each HARQ-ACK information bit does notprovide individual information; instead, all four HARQ-ACK informationbits are jointly considered to represent a HARQ-ACK state (set ofoutcomes for correct or incorrect detection of data TB(s) in respectivePDSCH(s)) for the Pcell and a HARQ-ACK state for the Scell using amapping as shown in Table 6 for M=3 or a mapping as shown in Table 7 forM=4.

In accordance with another embodiment of the present invention, a sameunderstanding is established between a UE and a serving NodeB for theinclusion of HARQ-ACK information in a PUSCH. Consequently, a servingNodeB is not required to detect whether a particular set of PUSCH REsconveys data information or HARQ-ACK information, because such detectionmay not be reliable. For HARQ-ACK signal transmission in a PUCCH, suchdetection is relatively simple as a NodeB can decide whether a signal istransmitted or not by merely computing the received energy in candidatePUCCH resources.

If a PUSCH transmission is scheduled by a UL SA through the transmissionof a corresponding PDCCH, the respective DCI format is assumed toinclude a DAI IE informing a UE whether or not a NodeB expects it totransmit HARQ-ACK information in a PUSCH. This DAI IE may also provideadditional information, e.g., the maximum number of PDSCH transmitted toa UE either in the Pcell or in the Scell, and the value of M can be setequal to this number. If a PUSCH transmission is SPS and not scheduledby a UL SA, then a UE may include HARQ-ACK information in a PUSCH forall DL subframes in a bundling window. M is then equal to the bundlingwindow size.

In order to include HARQ-ACK information in a PUSCH (when a NodeBexpects a UE to transmit HARQ-ACK information in a PUSCH), the HARQ-ACKstates as shown in Tables 4 or 5, for which a UE does not transmit aHARQ-ACK signal in a PUCCH, should be mapped to actual HARQ-ACKinformation bits in a PUSCH, when M=3 and M=4.

For M=3, the last state in Table 4 is overlapped with the second to laststate in Table 6 and both are represented by {0, 0, 0, 0} input bits toan RM encoder. Similarly, for M=4, the last two states in Table 5 areoverlapped with the {NACK, any, any, any} and the {NACK/DTX, any, any,any} states in Table 7 for the Pcell and the Scell, respectively, andare represented by {0, 0, 0, 0} input bits to an RM encoder.

FIG. 9 illustrates an encoding and decoding process of HARQ-ACK statesdepending on whether a transmission is in a PUCCH or in a PUSCH for M=3or M=4 subframes, according to an embodiment of the present invention.

Referring to FIG. 9, the encoding and decoding of the {DTX, any, any}state in the Pcell and of the {NACK/DTX, any, any} state in the Scellfor M=3 in step 910, and the encoding and decoding of the {DTX, any,any, any} state in the Pcell and of the {NACK/DTX, any, any, any} or the{ACK, NACK/DTX, any, any} state (except for {ACK, DTX, DTX, DTX} state)in the Scell for M=4 in step 920 depends on whether HARQ-ACK informationis to be transmitted in a PUCCH or in a PUSCH in step 930. When HARQ-ACKinformation is to be transmitted in a PUCCH, there is no HARQ-ACK signaltransmission for these HARQ-ACK states in step 940. When HARQ-ACKinformation is to be transmitted in a PUSCH, {0, 0, 0, 0} bits are usedto represent these HARQ-ACK states in step 950.

FIG. 10 illustrates block diagram of a transmitter for data and HARQ-ACKin a PUSCH, according to an embodiment of the present invention.Specifically, in FIG. 10, a representation of HARQ-ACK information bitsdepends on the number of cells a UE is configured and on whether eachHARQ-ACK information bit informs of an outcome for a respective PDSCHreception in a respective cell or whether all HARQ-ACK information bitsjointly inform of HARQ-ACK states corresponding to M PDSCH receptions inboth cells.

Referring to FIG. 10, if a UE is configured with one cell or if a UE isconfigured with two cells and it is M≤2, each HARQ-ACK information bitcorresponds to an outcome (ACK or NACK/DTX) of a respective PDSCHreception as described with reference to FIG. 5. However, if a UE isconfigured with two cells and M>2, a UE transmitter as illustrated inFIG. 10 operates similarly to the transmitter of FIG. 5, except that theoutcomes for M PDSCH receptions (combinations of ACK and NACK/DTX) foreach of the two cells 1010 form two respective HARQ-ACK states, whichare provided to a mapper 1020, as described for example in Table 6 forM=3 and Table 7 for M=4, which then generates the HARQ-ACK informationbits 1030, which are provided to an RM encoder.

FIG. 11 illustrates a block diagram of a receiver for data and HARQ-ACKin a PUSCH, according to an embodiment of the present invention.Specifically, in FIG. 11, a representation of HARQ-ACK information bitsdepends on the number of cells a UE is configured and on whether eachHARQ-ACK information bit informs of an outcome for a respective PDSCHreception in a respective cell or whether all HARQ-ACK information bitsjointly inform of HARQ-ACK states corresponding to M PDSCH receptions inboth cells.

Referring to FIG. 11, if a UE is configured with one cell or if a UE isconfigured with two cells and it is M 2, each HARQ-ACK information bitcorresponds to an outcome (ACK or NACK/DTX) of a respective PDSCHreception, as described with reference to FIG. 6. However, if a UE isconfigured with two cells and M>2, a NodeB receiver as illustrated inFIG. 11 operates similarly to the receiver illustrated in FIG. 6, exceptthat a decoder output for HARQ-ACK information bits 1110 is provided toa mapper 1120, e.g., as described in Table 6 for M=3 or Table 7 for M=4,which then generates two HARQ-ACK states representing outcomes 1130 forM PDSCH receptions (combinations of ACK and NACK/DTX) for each of thetwo cells.

One or more blocks in a transmitter and a receiver described inembodiments of the present invention can be implemented into acontroller and the controller generates or receives acknowledgement bits(i.e. acknowledgement information) according to the present invention.

While the present invention has been shown and described with referenceto certain embodiments thereof, it will be understood by those skilledin the art that various changes in form and details may be made thereinwithout departing from the spirit and scope of the present invention asdefined by the appended claims and their equivalents.

What is claimed is:
 1. A method for transmitting acknowledgementinformation by a user equipment (UE) in a communication system, themethod comprising: receiving one or more data transport blocks (TBs) inone or more downlink data channels over transmission time intervals(TTIs); obtaining acknowledgement information comprising fouracknowledgement information bits, jointly representing a state ofreception results for a plurality of data TBs, wherein a number of theplurality of data TBs is greater than a number of the acknowledgementinformation bits, the UE is configured for reception of the one or moredownlink data channels from two cells, and a number of the TTIs is threeor four; Reed-Mueller (RM) encoding the acknowledgement informationbits; and transmitting the RM encoded acknowledgement information bitson an uplink data channel, wherein one of the state of reception resultsis represented as {NACK, any, any, any} and {NACK/DTX, any, any, any}for a first cell and a second cell of the two cells, respectively, or isrepresented as {NACK, any, any} and {NACK/DTX, any, any} for the firstcell and the second cell, respectively, by the acknowledgementinformation bits {0, 0, 0, 0}, and wherein the ‘NACK’ indicates anegative acknowledgement (ACK), the ‘DTX’ indicates discontinuoustransmission, and the ‘any’ indicates either an ACK, a NACK, or DTX. 2.The method of claim 1, further comprising multiplexing the RM encodedacknowledgement information bits with uplink data.
 3. The method ofclaim 1, further comprising generating acknowledgement informationrespectively representing reception results for the one or more data TBsby corresponding acknowledgement information bits.
 4. The method ofclaim 1, wherein the acknowledgement information indicates correctdetection, if all of the one or more data TBs were correctly detected,and wherein the acknowledgement information indicates incorrectdetection, if at least one of the one or more data TBs was incorrectlydetected by the UE.
 5. The method of claim 1, wherein theacknowledgement information indicates incorrect detection, if the UEdoes not detect a data TB or a control channel releasing transmission ofa downlink data channel in a TTI.
 6. A user equipment (UE) fortransmitting acknowledgement information in a communication system, theUE comprising: a receiver configured to receive one or more datatransport blocks (TBs) in one or more downlink data channels overtransmission time intervals (TTIs); a controller configured to obtainacknowledgement information comprising four acknowledgement informationbits, jointly representing a state of reception results for a pluralityof data TBs, wherein a number of the plurality of data TBs is greaterthan a number of the acknowledgement information bits, the UE isconfigured for reception of the one or more downlink data channels fromtwo cells, and a number of the TTIs is three or four; a Reed-Mueller(RM) encoder configured to RM encode the acknowledgement informationbits; and a transmitter configured to transmit the RM encodedacknowledgement information bits on an uplink data channel, wherein oneof the state of reception results is represented as {NACK, any, any,any} and {NACK/DTX, any, any, any} for a first cell and a second cell ofthe two cells, respectively, or represented as {NACK, any, any} and{NACK/DTX, any, any} for the first cell and the second cell,respectively, by the acknowledgement information bits {0, 0, 0, 0}, andwherein the ‘NACK’ indicates a negative acknowledgement (ACK), the ‘DTX’indicates discontinuous transmission, and the ‘any’ indicates either anACK, a NACK, or DTX.
 7. The UE of claim 6, further comprising amultiplexer configured to multiplex the RM encoded acknowledgementinformation bits with uplink data.
 8. The UE of claim 6, wherein thecontroller is further configured to generate acknowledgement informationrespectively representing reception results for the one or more data TBsby corresponding acknowledgement information bits.
 9. The UE of claim 6,wherein the acknowledgement information indicates correct detection, ifall of the one or more data TBs were correctly detected, and wherein theacknowledgement information indicates incorrect detection, if at leastone of the one or more data TBs was incorrectly detected by the UE. 10.The UE of claim 6, wherein the acknowledgement information indicatesincorrect detection, if the UE does not detect a data TB or a controlchannel releasing transmission of a downlink data channel in a TTI. 11.A method for receiving acknowledgement information by a base station ina communication system, the method comprising: transmitting one or moredata transport blocks (TBs) in one or more downlink data channels overtransmission time intervals (TTIs); receiving, on an uplink data channelfrom a user equipment (UE), acknowledgement information comprising fouracknowledgement information bits, jointly representing a state oftransmission results for the one or more data TBs, wherein a number ofthe data TBs is greater than a number of the acknowledgement informationbits, the UE is configured for reception of the one or more downlinkdata channels from two cells, and a number of the TTIs is three or four;and Reed-Mueller (RM) decoding the received acknowledgement informationbits, wherein one of the state of transmission results is represented as{NACK, any, any, any} and {NACK/DTX, any, any, any} for a first cell anda second cell of the two cells, respectively, or represented as {NACK,any, any} and {NACK/DTX, any, any} for the first cell and the secondcell, respectively, by the acknowledgement information bits {0, 0, 0,0}, and wherein the ‘NACK’ indicates a negative acknowledgement (ACK),the ‘DTX’ indicates discontinuous transmission, and the ‘any’ indicateseither an ACK, a NACK, or DTX.
 12. The method of claim 11, furthercomprising de-multiplexing the RM decoded acknowledgement informationbits.
 13. The method of claim 11, further comprising receivingacknowledgement information respectively representing transmissionresults for the one or more data TBs by corresponding acknowledgementinformation bits.
 14. A base station for receiving acknowledgementinformation in a communication system, the base station comprising: atransmitter configured to transmit one or more data transport blocks(TBs) in one or more downlink data channels over transmission timeintervals (TTIs); a receiver configured to receive, on an uplink datachannel from a user equipment (UE), acknowledgement informationcomprising four acknowledgement information bits, jointly representing astate of transmission results for the one or more data TBs, wherein anumber of the data TBs is greater than a number of the acknowledgementinformation bits, the UE is configured for reception of the one or moredownlink data channels from two cells, and a number of the TTIs is threeor four; and a Reed-Mueller (RM) decoder configured to RM decode thereceived acknowledgement information bits, wherein one of the state oftransmission results is represented as {NACK, any, any, any} and{NACK/DTX, any, any, any} for a first cell and a second cell of the twocells, respectively, or represented as {NACK, any, any} and {NACK/DTX,any, any} for the first cell and the second cell, respectively, by theacknowledgement information bits {0, 0, 0, 0}, and wherein the ‘NACK’indicates a negative acknowledgement (ACK), the ‘DTX’ indicatesdiscontinuous transmission, and the ‘any’ indicates either an ACK, aNACK, or DTX.
 15. The base station of claim 14, further comprising ade-multiplexer configured to de-multiplex the RM decoded acknowledgementinformation bits.
 16. The base station of claim 14, wherein the receiveris further configured to receive acknowledgement informationrespectively representing transmission results for the one or more dataTBs by corresponding acknowledgement information bits.
 17. The basestation of claim 14, wherein another one of the state of transmissionresults is represented as {DTX, any, any, any} and {NACK/DTX, any, any,any} for a first cell and a second cell of the two cells, respectively,or represented as {DTX, any, any} and {NACK/DTX, any, any} for the firstcell and the second cell, respectively, by the acknowledgementinformation bits {0, 0, 0, 0}.
 18. The method of claim 1, whereinanother one of the state of transmission results is represented as {DTX,any, any, any} and {NACK/DTX, any, any, any} for a first cell and asecond cell of the two cells, respectively, or represented as {DTX, any,any} and {NACK/DTX, any, any} for the first cell and the second cell,respectively, by the acknowledgement information bits {0, 0, 0, 0}. 19.The UE of claim 6, wherein another one of the state of transmissionresults is represented as {DTX, any, any, any} and {NACK/DTX, any, any,any} for a first cell and a second cell of the two cells, respectively,or represented as {DTX, any, any} and {NACK/DTX, any, any} for the firstcell and the second cell, respectively, by the acknowledgementinformation bits {0, 0, 0, 0}.
 20. The method of claim 11, whereinanother one of the state of transmission results is represented as {DTX,any, any, any} and {NACK/DTX, any, any, any} for a first cell and asecond cell of the two cells, respectively, or represented as {DTX, any,any} and {NACK/DTX, any, any} for the first cell and the second cell,respectively, by the acknowledgement information bits {0, 0, 0, 0}.